Fitted roof bars = lots of noise

[MikesVX80]

I fitted 3x Toyota roof bars to my LC80 last weekend, ready for when I need to mount my RTT. Have to say, the wind noise at 60mph is much more than I expected, even with the sunroof blind shut!! Is this to be expected? Must be even worst with a whopping great roof rack??

Mine also has one of those sunroof "spoilers" which has always added a fair bit of wind noise and thus I've never really seen the point of - I wonder if that is adding to it? Might remove it and see!

 

[clivehorridge]

I have a big ARB rack, of course it creates some noise but its not really noticeable.

Would imagine that yours with the RTT mounted, will go as good as silent.

 

[Dave2000]

I have seen a lot of roof racks modified with a spoiler at the front, just a simple deflector made from a piece of shaped ally, apparently helps? I have also found if the roof is not adjusted correctly it seems to let in more noise.

regards

Dave

 

[MikesVX80]

OK, thanks guys. Might just remove the rails for now until the RTT goes on, will also look at adjusting the sunroof!

 

[Dave2000]

Whilst trying to avoid the hijack but somewhat relevant, my sunroof when shut correctly there is an annoying rattle which I think comes from the pop up wind deflector, pulling the blind shut tight stops the noise until I hit some rough tracks and the vibration allows the blind to work itself slightly open and the noise returns. A touch of the button lifts the roof slightly and the rattle stops, of course when I switch off the ignition I get a warning every time that the roof is not quite shut. Now when the roof is fully open the wind noise is very high (of course I hear you say) but, if I pull down the wind deflector probably no more than a quarter of an inch the wind noise is gone and I mean completely gone. Despite checking everything I cannot see any reason for this, either a, the deflector is always the source of noise and is how it came from the factory or, keeping in mind the rattle I have some wear somewhere?

Looking again at Mikes opening post I appreciate that a breeze block shape doing 60 MPH is going to generate plenty of turbulence but it is EXACTLY that speed when mine is at it's noisiest unless the deflector is pulled down/and or the roof is lifted ever so slightly? Perhaps the roof mechanism wears at a certain point and we become accustomed to it over time. A good experiment would be if readers could try pulling the deflector down slightly with the roof fully open reduces the noise? I would add this does not work when kids are on board.

I am thinking if Mikes noise from the roof bars is getting into the cabin, then perhaps this would happen on all cruisers if there is the slightest misalignment/adjustment/wear would make a lot of difference to the noise he is experiencing?

regards

Dave

 

[StarCruiser]

Mike, as an experiment, after reading Dave's post about the wind deflector with interest, if these are the type of roof bar that go from gutter to gutter (I realise I may have this wrong here) can you try moving the front one forwards and /or backwards to see if there is a point the noise goes away?

I'm thinking that the air coming up off the windscreen is going to create some turbulence as it clears the rake of the windscreen and goes over the roof. The positioning of the bar, like the height of the sun roof wind deflector, and how it interacts with the turbulence may have a bearing on the noise you hear in the car.

 

[clivehorridge]

Two comments re the above:

1. It doesn't take much to create a noise. I drove a Terrano for 5 years, never any wind noise until someone moved the angle of the shortwave radio we had on board, it was no longer than 9" and about 5mm Dia. but changing the rake from about 40 degrees to 60 degrees made a hell of a din.

2. My sunroof rattles, but it's the inside trim where the longitudinal trim meets the front transverse trim. Took me a year to find that rattle.

 

[Gary820]

Got to say I don't get loads of noise with the roof open, until the waffle boards are on the rack then it's gets a bit noiser.

 

[Dave]

Does anyone have a part number/picture of the Toyota roof rack rails? I'm looking for just one for my rear awning.

 

[Dave2000]

Got to say I don't get loads of noise with the roof open, until the waffle boards are on the rack then it's gets a bit noiser.

Have you actually tried to pull the deflector down just a tad (no waffle boards ect) to see if the noise reduces Gary? Noise is subjective, so it would be interesting if lowering the deflector made any difference, it might point to why mine rattles?

regards

Dave

 

[MikesVX80]

Dave2000 - which deflector are you talking about? I have a solid plastic one mounted to the front edge of my sunroof, much like the plastic Toyota bonnet protector that is also fitted to my car (and the plastic window deflectors many people have) - I think this could be a source of the wind noise when the sunroof is closed and without the roofbars fitted to be honest. Is there another "pop-up" wind deflector in the mechanism somewhere? I haven't looked to be honest, and I'm not with the car currently!

StarCruiser - I can certainly give that a go, at the moment the bar is mounted directly above the B-pillar for maximum support when the rooftent is fitted, but I doubt an inch either way would make much difference.

Does anyone have a part number/picture of the Toyota roof rack rails? I'm looking for just one for my rear awning.

I can get you that info at the weekend if you can wait until then? Mine are genuine Toyota but look pretty similar to a Thule roof bar...

 

[Dave2000]

The stock sun roof with no additions has a small deflector that rises when you open the roof is the source of the noise on mine, as mentioned pulling it down a tiny amount completely stops the wind noise, IMO that was the original design idea. I am coming to the conclusion mine is worn or out of adjustment?

regards

Dave

 

[MikesVX80]

The stock sun roof with no additions has a small deflector that rises when you open the roof is the source of the noise on mine, as mentioned pulling it down a tiny amount completely stops the wind noise, IMO that was the original design idea. I am coming to the conclusion mine is worn or out of adjustment?

Sounds like it! Can you not put a cable tie on the deflector to restrict its upward movement?

 

[Dave2000]

Sounds like it! Can you not put a cable tie on the deflector to restrict its upward movement?

Possibly Mike, at the moment my time is consumed with time with the electric cooling fan/solar panel fixing mods at the moment, when I get five minutes spare I will have a look, it is possible that the rattle I get when the roof is closed (but the blind is open) is caused by the same problem, perhaps there is an adjustment?

Get back to you,

regards

Dave

 

[MikesVX80]

Mike, as an experiment, after reading Dave's post about the wind deflector with interest, if these are the type of roof bar that go from gutter to gutter (I realise I may have this wrong here) can you try moving the front one forwards and /or backwards to see if there is a point the noise goes away?

I'm thinking that the air coming up off the windscreen is going to create some turbulence as it clears the rake of the windscreen and goes over the roof. The positioning of the bar, like the height of the sun roof wind deflector, and how it interacts with the turbulence may have a bearing on the noise you hear in the car.

Hi Starcruiser, as requested/suggested I moved the front roof bar rearwards by approx 3", so instead of being directly above the B-pillar it sits above the mounting point for the interior grab handle for rear passengers. This has reduced wind noise slightly but noticeably, so whilst it's still a bit noisy, it's not as bad!

 

[StarCruiser]

Interesting, and thanks for the update. I usually have my front bar in the middle of the sunroof. It's not mouse quiet but it doesn't notice too much.

Glad my theory holds water. I might even experiment with mine, though I do try and remove them when not in use thinking all that wind resistance must be sipping additional fuel somewhere along the line.

 

[MikesVX80]

Interesting, and thanks for the update. I usually have my front bar in the middle of the sunroof. It's not mouse quiet but it doesn't notice too much.

Glad my theory holds water. I might even experiment with mine, though I do try and remove them when not in use thinking all that wind resistance must be sipping additional fuel somewhere along the line.

To be honest, mine is very much a second vehicle so fuel consumption isn't a major concern, and thus out of laziness I'll probably leave them on there! I need to see how the rooftent sits on the bars before I decide on their final position, ideally I'd like the bars to sit above the B and C pillars for maximum support/strength, particularly when offroad, but we'll see..!